Devices are known in the art to capture images described by contact on a surface. A primary, although by no means exclusive, application for such imaging devices is in the area of fingerprinting, whether for security, forensics or other purposes. Other applications include analysis of surface texture for classification or testing purposes, or recording contact for archival purposes, or possibly mechanical duplication.
All of the foregoing applications involve translating the image described by contact into a reproducible record of the image. For example, in the fingerprint application, a time-honored system is to “ink” the fingers and roll them on a paper or card surface. Of course, without further scanning of the results, such systems lack the capability to generate computer-ready signals representative of the images. Without the storage and analysis capabilities of a computer, cataloging and comparison of such fingerprint images is a time-consuming and unpredictable task.
More recent devices shine light onto the fingerprint via a prism. The reflected image may be captured on photosensitive film, or received onto a photosensitive array. In the latter case, the image may then be pixelated and stored as an analog or digital signal representative of the image. These signals are now available for further processing by computers.
The specification of co-pending, commonly assigned U.S. patent application IRRADIATED IMAGES DESCRIBED BY ELECTRICAL CONTACT IN THREE DIMENSIONS incorporated herein by reference (hereafter “Irradiated Images”), discloses an invention that generates images described by contact, in which the contact itself closes an open circuit to generate radiation in a pattern in register with the contact. In this way, an irradiated image results, which corresponds directly to the contact pattern energizing the radiation.
A preferred embodiment of Irradiated Images is enabled by a Polymer Thick Film (“PTF”) electroluminescent system without a rear electrode, in which a fingerprint is disposed to close the open circuit by making contact and thereby serving as a “temporary” rear electrode. The electroluminescent system then energizes in a pattern in register with the contact (i.e. the fingerprint) to emit a high-resolution image of visible light with high fidelity to the contact. This image may then be directed on to a photosensitive array suitable for conversion into an electrical signal representative of the image.
Irradiated Images emphasizes that it is in no way limited to fingerprinting applications. According to the invention, any form of electrically conductive contact will describe an irradiated image. Thus, the surface textures of many objects, animate or inanimate, may be imaged with the invention.
Further, Irradiated Images teaches that it is not limited to contact generating visible light via a PTF electroluminescent system. Although the preferred PTF embodiment is highly advantageous, Irradiated Images contemplates generation by contact of any radiation in the electromagnetic spectrum to enable the invention. Such contact-generated radiation may or may not be energized using an electroluminescent system, PTF or otherwise. For example, an infra-red image could be generated by an open circuit where heat is emitted in a pattern in register with selective closure of the circuit by the contact. Clearly, yet further fidelity and resolution of images described by contact may be available through selection of the wavelength of the radiation generated by the invention, as may be compatible with the device receiving and interpreting the irradiated image.
Moreover, Irradiated Images is not limited to imaging to two dimensions. Particularly when deployed using elastomeric electroluminescent lamp techniques such as disclosed in commonly-assigned U.S. Patents ELASTOMERIC ELECTROLUMINESCENT LAMP (hereafter “Elastomeric Lamps”) and ELECTROLUMINESCENT SYSTEM IN MONOLITHIC STRUCTURE, (hereafter “EL Monolithic Structure”), the disclosures of which applications are fully incorporated by reference herein, Irradiated Images allows true three-dimensional images to be taken of three-dimensional surfaces. The membranous properties of elastomeric lamp layers such as disclosed in the above-referenced patents facilitate deploying Irradiated Images on such a three-dimensional surface. So deployed, a three-dimensional image can be energized that is in register with corresponding three dimensional contact. This image may then be converted to an electrical signal that is representative of the three-dimensional contact without approximation or projection from a planar or two-dimensional state.
The foregoing exemplary image-generation mechanisms all require a receptor device for images to be memorialized for later processing. The processing power of computers becomes enabled when such receptors generate digital representations of the images. It would therefore be highly advantageous to provide a two- or three-dimensional addressable receptor in laminate form capable of generating such digital representation of images. It would be further advantageous to provide such an addressable receptor whose design lent itself to construction in PTF form. Such an addressable PTF receptor would be reliable and inexpensive to manufacture, especially if made in accordance with techniques such as are disclosed in co-pending, commonly-owned U.S. patent applications MEMBRANOUS MONOLITHIC EL STRUCTURE WITH URETHANE CARRIER (hereafter “Urethane Carriers”) and MEMBRANOUS EL SYSTEM IN UV-CURED URETHANE ENVELOPE (hereafter “UV-curable EL”), the disclosures of which applications are incorporated herein by reference. Moreover, such an addressable PTF receptor would be highly compatible with the image-generating devices such as taught by Irradiated Images in both two- and three-dimensional deployments.